1. Field of the Invention
The invention relates to a composite tool comprising a metallic supporting part and at least one such working part of different material compositions, which parts are metallically joined together, in particular a saw blade or a bandsaw.
2. Discussion of Background Information
Tools on which the highest demands are made regarding the working part and the holding part or clamping part are usually made of different materials, with the respective material being selected to be the best possible for the strains on the part.
It is known to make saw blades or bandsaws out of a so-called bimetal strip, which strip is formed of a tenacious supporting part and a cutting part. While the supporting part is made of an alloy that ensures high elasticity, toughness, fracture-resistance and the like properties, the cutting part, which ultimately forms the cutting tooth tips, features a high material hardness, abrasion resistance and a like wear-resistance. Such saws have been part of the prior art for a long time, and the cutting part, formed, e.g., of high-speed steel, may be metallically bonded to the carrying or supporting part by welding. If, according to another possibility, the cutting tips are made of special materials, e.g., hard metal, they are to be bonded to the supporting part individually, in particular by brazing.
In the cutting of materials, the hardness, toughness and abrasion resistance of the tool blade usually determine the service life thereof in practical use. Hard material coatings are also often provided in the blade area of the tools in order to increase their cutting yields.
However, the cutting yield of cutting tools depends not only on the hardness of the blades and their abrasion resistance and toughness, but is also considerably influenced by the properties of the material to be cut. For instance, titanium, austenitic steels, nickel-based alloys and the like are known as materials that are difficult to cut. In a treatment of the above materials, it is often only possible to achieve low cutting yields with extremely high tool wear, even with high quality high-speed steels and hard metals. Roundnesses and craters in the blade area are usually the cause of the failure of the tool.
The invention is intended to remedy this situation, the object being to disclose a composite tool that has improved cutting properties of the working part. It is, in particular, the object of the invention to provide a tool for cutting titanium and titanium alloys, austenitic steels, nickel- and cobalt-based alloys and the like.